The present invention relates to a wrench, and more particularly to a wrench that enables tightening and loosening of a hex bolt in only one continuous operation without the need of repeated removing and replacing of the wrench from and onto the hex bolt.
When using a conventional wrench to tighten or loosen a hex bolt or any tube, post, bar, etc. having a polygonal cross section, a user needs to repeatedly turn the wrench, removing and replacing the wrench from and onto the hex bolt or the polygonal tube, post or bar, and turning the wrench again. These repeated movements are, of course, very bothersome to the user.
Taiwan Patent Application No. 76209415 entitled xe2x80x9cQuick Wrench with Adjustable Clamp Spacexe2x80x9d discloses a wrench having a handle, and a movable jaw block pivotally connected to an end of the handle via a movable shaft. The movable jaw block is manually displaced and returnable to its original position via a return spring. When a user uses the wrench to tighten or loosen, for example, a hex bolt to a certain degree and has to continue the tightening or loosening movement, he or she may use, for example, a thumb to depress a rear end of the movable jaw block to release the jaw block from clamping the hex bolt. At this point, the user may lift the handle of the wrench to a proper position and then release the movable jaw block to restore its clamping state, and then turn the handle again to tighten or loosen the hex bolt further.
With the wrench disclosed in Taiwan Patent Application No. 76209415, the user still needs an additional movement to depress the movable jaw block to release the same from a clamping state, instead of manipulating the handle in one continuous movement to complete the tightening or loosening of the hex bolt. In other words, the movable jaw block must be repeatedly depressed and released for the user to complete the tightening or loosening of the hex bolt with the wrench in a manner close to the desired one-movement manipulation. As mentioned in the Quick Wrench with Adjustable Clamp Space disclosed in Taiwan Patent Application No. 76209415, the movable jaw block is repeatedly depressed and released to change the clamp space, so that the wrench could be continuously manipulated to tighten or loosen the hex bolt. For users, such repeated depressing and releasing of the movable jaw block still causes considerable inconvenience to them.
It is therefore a primary object of the present invention to provide an improved wrench that enables a user to tighten or loosen, for example, a hex bolt in one continuous movement without the need of removing and replacing the wrench from and onto the hex bolt for a next turning of the wrench to tighten or loosen the hex bolt further.
To achieve the above and other objects, the wrench of the present invention mainly includes a handle having an expanded head portion formed into two spaced and parallel plates to define a clearance therebetween, a first jaw block having a rearward extended sectorial portion pivotally connected to the expanded head portion of the handle to either locate in or partially move out of the clearance, a second jaw block movably connected to the first jaw block to define a variable clamp space between them, and a rotating unit mounted on the first jaw block for adjusting an openness of the clamp space. A slip stopper is provided in the expanded head portion of the handle and adapted to move to a position that allows the first jaw block to elastically move out of or locate in the clearance.
When using the wrench of the present invention to tighten or loosen, for example, a hex bolt to a certain degree, a user needs only to pull the handle in a direction opposite to that in which a force is applied on the handle to tighten or loosen the hex bolt, so that the clamp space on the first jaw block is caused to instantaneously slip and turn relative to the clamped hex bolt, allowing the user to apply a force on the handle again without the need of repeatedly removing and replacing the wrench from and onto the hex bolt.